Quinlan Vos is one of the trickier inclusions here, as he is arguably first and foremost an Expanded Universe character (who starred in many comics), except his appearance was always based on an incredibly obscure background character in The Phantom Menace. Lucasfilm has since embraced that that random guy little Anakin walks by in Mos Espa is in fact Vos himself, who's also name-dropped in Revenge of the Sith. He only made one appearance on The Clone Wars, teaming up with Obi-Wan to fight Cad Bane. His portrayal on the series positioned him as a notably more cocky guy than the intense and conflicted Jedi from the EU stories.

Orn Free Taa

First seen in The Phantom Menace

The corpulent Twi'lek senator could be seen throughout the prequels, but didn't have much to say. That's changed on The Clone Wars though, as he's been a frequent presence, advocating for his people and forming an uneasy alliance with enemy freedom fighters on Ryloth.

Originally the right hand man to Chancellor Valorum, Mas Amedda got a couple of minutes of screen time in Attack of the Clones and Revenge of the Sith as well, always by the side of Palpatine. On The Clone Wars, Amedda appears several times in the same capacity and, as we saw in Sith, is very much of the same mind as his boss - often helping push forward Palpatine's agenda, even while maintaining an air of being more open-minded.

Barriss Offee

First seen in Attack of the Clones

One of the many Jedi who took part in the Battle of Geonosis in ATOC, Barriss Offee's position as Luminara's padawan in the EU was held over in The Clone Wars. She and Ahsoka had a memorable team-up in Season 2, as we saw their differing approaches and how they ultimately bonded in the midst of a situation that saw them nearly die together. The end of Season 5 involved Barriss in a huge way, as she was revealed as the Jedi behind a bombing that Ahsoka was framed for and we learned how she'd completely turned her back on the Jedi for their actions during the Clone Wars. Barriss' betrayal was one of the more dramatic deviations and overwriting of the EU; always a source of controversy for some fans.

It was easy to miss Baron Papanoida in Revenge of the Sith, as he was briefly seen on the side of the screen, as Anakin Skywalker entered an opera house. But he's pretty important, considering he created the entire Star Wars universe! Well, okay, the Baron didn't, but George Lucas, who played him, did. On The Clone Wars, we saw Papanoida take the spotlight in the episode "Sphere of Influence," as his daughters were kidnapped. He may have seemed unassuming at first, but in a very amusing moment (given who Papanoida is made to look like), we saw the Baron prove he could hold his own in battle, as he whipped out two blasters during a tense situation in a very familiar cantina on Tatooine.

Bossk

First seen in The Empire Strikes Back

Why do we love Bossk from The Empire Strikes Back? It's the toe and the snarl, pretty much. Like most of the bounty hunters in Empire, he might not have done much, but damn if he still wasn't memorable. In The Clone Wars, we have gotten to see Bossk decades earlier, operating alongside other bounty hunters like Aurra Sing – and perhaps influencing a troubled young man by the name of Boba Fett, who he'd continue to work with on several more missions.

Tarpals

First seen in The Phantom Menace

In The Phantom Menace, Tarpals was one of the only Gungans besides Jar Jar to speak, though it included the less than fortunate line, "You-sa in big doo-doo dis time!" On The Clone Wars however, Tarpals actually got a rather poignant and powerful portrayal - if you could overcome residual Gungan hatred that is. Over the course of a couple of episodes, we saw he was a competent military leader and he got a legitimately great death, in an intense fight with General Grievous in which he sacrificed himself to get close enough to do some real damage to his enemy. He also stands out as one of the more unsettling depictions of death on the show, as we saw him laying on the ground with a dead man stare.

Commander Gree

First seen in Revenge of the Sith

While Commander Cody's name was spoken aloud and he got a few buddy-buddy moments with Obi-Wan in Revenge of the Sith to establish a rapport, Commander Gree was one of those "Only I.D.'ed by the toys" type of Clone Troopers - but he was part of a crowd-pleasing moment to be sure, when he and another Clone attempted to kill Yoda after Order 66 was given, only to be decapitated by the Jedi master. On The Clone Wars, we see Gree as a determined and very loyal soldier, who greatly values following orders. While Season 6 will explore Order 66 more, Gree's attitude obviously casts a shadow, as we know what he will try to do down the line, even after fighting alongside Yoda and the Jedi.